THURSDAY, Oct. 1, 2026 (HealthDay News) — You're up to four times more prone to losing a nail after you start a GLP-1 medicine than before, a new study suggests.
Risk for nail discoloration also rises when taking GLP-1s, according to a French study. The findings were presented Wednesday in Vienna at the annual meeting of the European Academy of Dermatology and Venereology.
“Until now, nail changes associated with GLP-1 therapies had essentially been anecdotal,” study co-author Dr. Charles Taïeb noted in a meeting news release. He's a clinical dermatologist at Necker University Hospital in Paris.
A second study presented at the meeting found that people taking a GLP-1 were also more prone to hair loss and scalp issues.
In the first study, Taïeb and colleagues compared nail changes in 1,904 people with type 2 diabetes and/or obesity — 575 who were using a GLP-1 and 1,329 who had never used the drugs.
Overall, 66% of GLP-1 users reported some kind of nail disorder, compared to 53% of non-users, the researchers said.
The odds for "nail detachment" quadrupled among GLP-1 users compared to non-users, and 46% of GLP-1 users reported nail discoloration compared to 17% of non-users.
The nail changes weren't all due to weight loss, because the higher risks remained for GLP-1 users when the researchers focused on people in both groups who'd lost weight with or without GLP-1s.
It's not clear whether GLP-1 meds are the cause of the nail problems, since half of people who used the drugs said they'd had nail issues before starting their treatment.
However, even after the researchers adjusted for that, GLP-1 users remained two to three times more prone to nail detachment and/or discoloration, compared to non-users.
In the second study, researchers led by Parisian dermatologist Dr. Bruno Halioua compared hair loss among the same 1,904 people with type 2 diabetes and/or obesity.
They report that 50% of GLP-1 users had unusual levels of hair loss compared to 34% of non-users. Loss of hair volume/density was also reported by 42% of GLP-1 users and 19% of non-users.
Soon after treatment began, 26% of GLP-1 users reported unusual hair loss, compared to 12% of those who weren't being treated with the drugs, Halioua's team said.
Scalp redness and itching often accompanied the hair loss, the researchers added.
“This suggests that what is happening on the scalp may go beyond the classical shedding seen after rapid weight loss and involve an inflammatory component,” Halioua explained in a meeting news release. “Scalp inflammation was the rule rather than the exception, which clinicians do not currently look for and which may be treatable."
Halioua said the current study cannot prove cause and effect, but a more rigorous, prospective trial is planned that would track hair, scalp and nail changes right from the start of GLP-1 treatment.
His advice? Balance the benefits of weight loss against any changes to hair or nails.
“These changes are frequent, usually benign, and are not a reason to stop an effective treatment on one’s own initiative,” Halioua said. “Anyone who notices hair shedding, an itchy or red scalp or nail changes should mention it to their doctor rather than discontinue therapy.”
Because these findings were presented at a medical meeting, they should be considered preliminary until published in a peer-reviewed journal.
More information
Find out more about GLP-1 medications at Stanford University.
SOURCES: European Academy of Dermatology and Venereology, news release, abstracts, Sept. 30, 2026
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